This invention is directed to an improvement within a short length or regular walker in the form of an immobilization brace with uniform adjustable compression, which is the subject of U.S. Pat. No. 5,370,133 issued Dec. 6, 1994, and assigned to the common assignee. Such brace consisted of a semi-flexible molded polyurethane boot closed at the rear and sides and open at the front, surrounding a preferably breathable open pore foam inner liner which covers the lower leg, ankle and foot of a patient. A boot front portion is fixed to a walking sole having a minimal rocker effect and of minimal thickness. The foot portion of the boot has a rounded heel counter and a contoured foot bed with a shock absorbing foam insole within the boot portion to recess pad the plantar surface of the sole. The dorsum of the boot and the boot upper are provided with spaced ventilation ports or windows to ventilate the leg, ankle and foot of the user through the porous open foam liner. The dorsum of the boot and the boot upper are provided with spaced, adjustable, leverage-type closures to provide adjustable general compression and focal compression to assure a proper fit of the brace and to reduce edema induced swelling throughout the leg, ankle and foot. The boot upper and boot foot portions may be separately formed of two parts hinged together, but preferably locked to prevent fore and aft rotation of the boot upper relative to the foot portion fixed to the sole. In such immobilization brace assemblies, patients enjoy the same hard shell, circumferential protection as a plaster or like cast, while additionally, unlike casts, the immobilization brace of U.S. Pat. No. 5,370,133 does not loose its effectiveness as edema subsides and muscles begin to atrophy. Further, the leverage fasteners, similar to ski boot buckles being attached directly to the molded plastic shell, provide controlled compression and immobilization throughout the healing process without becoming a tangled mess like hook and loop velcro closures. As the shape of the lower leg changes during the healing process, the outer shell portion moves to conform and reconform one click at a time.
However, during use, the patients wearing the immobilization brace of the prior patent express a major complaint that such immobilization assembly is extremely hot in spite of the ports or windows within the molded plastic outer boot dorsum and upper portions.
It is therefore a primary object of the present invention to provide such immobilization brace assemblies with air ventilation ports or windows appropriately carried by the inner liner which extends therethrough, which are preferably of elongated form so as to cross and overlap a series of spaced ventilation ports within the molded plastic outer boot to readily cause exterior air to penetrate directly to the skin of the user and allow body heat to be released without materially adversely affecting the snug fit of the boot and liner assembly about the leg, ankle and foot of the user.
It is a further object of the invention to provide the liner component of the assembly with loose woven, open mesh material sewn over the ventilation ports within the liner to keep the elongated ports within the liner from spreading out of shape, while further keeping the soft tissue of the user from pushing through the liner ports, particularly in the case of edema.
Other advantages of the present invention will become apparent from the description of the preferred embodiment and from the accompanying drawings.